Door assembly

ABSTRACT

APPARATUS ADAPTED TO SUPPORT A ONE-PIECE, UPWARDLY ACTING DOOR FOR MOVEMENT BETWEEN A SUBSTANTIALLY HORIZONTAL, OPENED POSITION AND A SUBSTANTIALLY UPRIGHT CLOSED POSITION CLOSELY ADJACENT WALL MEANS HAVING AN OPENING CLOSED BY SAID DOOR WHEN IN THE CLOSED POSITION. THE APPARTUS INCLUDES A PAIR OF SPACED, HORIZONTAL AND PARALLEL TRACKS FOR GUIDING A PAIR OF ROLLERS MOUNTED ON THE UPPER   END OF THE DOOR AND A PAIR OF SPACED, PARALLEL AND UPRIGHT TRACKS FOR GUIDING A PAIR OF ROLLERS MOUNTED ON THE LOWER END OF THE DOOR. THE TWO PAIRS OF TRACKS HAVE CURVED END PORTIONS WHEREBY THE ENTIRE DOOR MOVES DOWNWARDLY AN ANGLE INTO THE CLOSED POSITION AGAINST THE WALL MEANS

March 9, 1971 P. E. PEMBERTON ErAL 3,568,365

5 Doon ASSEMBLY Filed May 16, 1969 5 Sheets-Sheet 1 a3 n.676? 1I MarchA 9, 1971 Filed May 16, 1969 /3 L2/ i! V+ P. E. PEMBERTON ETAL DOOR ASSEMBLY v 3 Sheets-Sheet 2 f77-L Q@ March s; 1971 P, E, PEMBERTON my V3,5665

DOOR ASSEMBLY 3 Sheets-Sheet 5 Filed May 16, 1969 United States Patent O 3,568,365 DOOR ASSEMBLY Paul E. Pemberton, Donald S. Harris, and Gail L. Thornburg, Dallas, Tex., assignors to Overhead Door Corporation, Dallas, Tex.

Filed May 16, 1969, Ser. No. 825,220 Int. Cl. E05d 15/38 U.S. Cl. 49--197 6 Claims ABSTRACT OF THE DISCLOSURE Apparatus adapted to support a one-piece, upwardly acting door for movement between a substantially horizontal, opened position and a substantially upright closed position closely adjacent wall means having an opening closed by said door when in the closed position. The apparatus includes a pair of spaced, horizontal and parallel tracks for guiding a pair of rollers mounted on the upper end of the door and a pair of spaced, parallel and upright tracks for guiding a pair of rollers mounted on the lower end of the door. The two pairs of tracks have curved end portions whereby the entire door moves downwardly at an angle into the closed position against the wall means.

BACKGROUND OF THE INVENTION This invention relates in general to an upwardly acting door assembly and, more particularly, to apparatus for supporting a one-piece door so that it is relatively easy to operate, but also capable of automatically moving into and remaining in a well-sealed, closed position.

Persons acquainted with the manufacture and used of doors used for refrigerators or fire walls, for example, are well aware of the difficulties previously encountered in providing a substantially airtight seal between the door and the wall means having the opening to be closed by the door. In the case of a refrigerator door, any substantial amount of air movement between the closed door and the wall means will produce a costly heat loss. Heretofore, to avoid such losses, refrigerator doors have been supported and operated so that they are often diicult to open, particularly an emergency arises. Thus, especially where the refrigerator door is relatively large, it is virtually a necessity to provide an emergency door through which humans can pass in case of an emergency. Many of the structural features in present doors, such as ponderous, self-locking latch mechanisms and closely litting guide rails, which give rise to the need for an emergency door in existing installations, are the very features provided for insuring a tight seal of existing doors with the wall around the opening which they cover. That is, for example, if a strong guide or latchng mechanism becomes jambed, personnel can be trapped within the refrigerator, unless an emergency exit is provided.

Accordingly, a primary object of this invention has been the provision of apparatus adapted to support a one-piece, upwardly acting door for movement into and out of an upright position of substantially airtight engagement with wall means defining an opening covered by the door means in its closed position.

A further object of this invention is the provision of apparatus, as aforesaid, wherein the force tending to hold the door in a closed and sealed positionis furnished by gravity and wherein the door can be moved into and out of its closed position with relative ease even where the door is of a large size, thereby eliminating the need for an emergency exit where, for example, the door is used to close a refrigerator.

Other objects and purposes of this invention will become apparent to persons familiar with this type of equip- Patented Mar. 9, 1971 ment upon reading the following descriptive material and examining the accompanying drawings, in which:

FIG. l is a broken, sectional viewof a door and doorsupporting apparatus embodying the invention, as viewed from the interior of the door and taken along the cutting line I-I in FIG. 2.

FIG. 2 is a sectional view taken along the line II-II in FIG. 1.

FIG. 3 is a sectional view taken along the line III-III in FIG. l.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 1.

FIG. 5 is a fragmentary, sectional view substantially as taken along the line V-V in FIG. 2.

FIG. 6 is a sectional View taken along the line VI-VI in FIG. 2 and illustrating a modified construction.

FIG. 7 is a fragment of FIG. 2 showing a modified construction.

FIG. 8 is a broken, sectional View of a modified door assembly substantially as taken along the line II-II in FIG. 1.

For convenience in description, the terms upper, lower, left, right and words of similar import Will have reference to the door-supporting apparatus and door assembly as appearing in FIG. l. The terms interior or rear and exterior or front will have reference to the right and left sides, respectively, of the door and associated parts as appearing in FIG. 2. The terms inner, outer and derivatives thereof will have reference to the geometric center of said door assembly and its supporting apparatus.

SUMMARY OF THE INVENTION The objects and purposes of the invention, including those set forth above, have Ibeen met by providing a pair of spaced, parallel and substantially horizontal tracks Which extend away from a well near the upper end of and on opposite sides of an opening in the wall. A pair of substantially upright tracks extend along said opposite sides of said opening from points near the lower end thereof to points near said horizontal tracks. A one-piece door has a pair of rollers mounted near the upper end thereof for rolling engagement with the horizontal tracks and a pair of rollers mounted near the lower end thereof for rolling engagement within the upright tracks. The front ends of the horizontal tracks are curved downwardly and the lower ends of the upright tracks are curved frontwardly, whereby the direction of the linal movement of the dooi into the closed position is downwardly and frontwardly. Thus, gravity urges, and thereby holds, the door in a snugly closed position against adjacent portions of the Wall surface surrounding the opening therein.

DETAILED DESCRIPTION The upwardly acting door assembly 10, a preferred embodiment of which is illustrated in FIGS. l and 2, is comprised of a one-piece door 11 and track structure 12 adapted to support said door for movement between a substantially horizontal open position and a substantially upright closed position. A counterbalance mechanism 13 is connected to the door 11 for counteracting the force of gravity and thereby facilitating the opening and closing of the door. The door may be opened manually or by a door operator, a fragment of which is indicated at 14 and supported upon the rail structure 16. A door operator capable of performing the opening and closing function is disclosed in a companion application entitled High Speed Door Operator and assigned to the assignee of this application.

The door 11 may be of any conventional type adapted to close a substantially rectangular opening 17 in an upright wall 18 and having a threshold 19. That is, the door may be fabricated from metal, wood, glass, plastic material, or any combination of such materials. The door is relatively rigid, but may be somewhat resiliently exible in order to absorb shocks. The door may be insulated for covering the entry to a large walk-in refrigerator or refrigerated room, or it might be insulated against heat where it is desired to use the door for closing and opening in a re wall.

In one embodiment of the invention, the marginal portions of the sides and top of the door overlie the portions of the wall 18k defining the side and top edges of the opening 17. A seal 22 (FIGS. 1, 2 and 3), which is preferably fabricated from a resiliently flexible material, such as rubber or plastic, is mounted either along the edge portions of the interior surface 21 of the wall or upon the marginal portion of the door so that it is compressed between these two portions when the door is in its closed position of FIG. 2. As shown in FIG. 3, the door 11 engages the seal 22 slightly before it reaches its closed, broken-line position of 22A. An elongated seal 20 of any conventional type is mounted upon the lower edges of the door 11 for sealing engagement with the threshold 19 when the door 11 is in the closed position of FIG. 2.

A pair of upright tracks 23 and 24 (FIG. l) are mounted upon the interior surface 21 of the wall 18 preferably adjacent the side edges of the door 11, when it is in its closed position, by means of brackets 26 and 27, respectively. The major and upper portions of the rails 23 and 24 are spaced rearwardly from the wall 18, but the lower end portions 28 and 29 are curved inwardly, as shown in lFIGS. 2 and 3, toward the wall 18 for reasons discussed hereinafter.

A pair of substantially horizontal tracks 32 and 33 (FIGS. 1, 2 and 4) are mounted on the interior side of lthe wall 18 at their front ends by means of brackets 34 and 3S, respectively. The rearward and intermediate portions of the tracks 32 and 33 are suspended from the ceiling 37, for example, by hangers 38. The tracks 32 and 33 are parallel and they extend rearwardly from points directly above the upright tracks 23 and 24. The front end portions 41 and 42 (FIGS. 4 and 2, respectively) of the tracks 32 and 33 are curved downwardly for reasons discussed hereinafter.

The tracks 23, 24 and 32, 33 preferably have substantially identical C-shaped cross sections. The upright tracks 23 and 24 have grooved flanges 43 and 44 on their front sides and the tracks 32 and 33 have grooved flanges 46 and 47 on their lower sides.

A pair of upper rollers 48 and 49 are mounted upon shafts 52 and 53, respectively, which are supported in brackets 54 and 55 secured to the interior surface of the door 11 at the opposite ends of the upper edge thereof. The rollers 48 and 49 are disposed within the tracks 32 and 33, and are rollingly engaged within the grooved flanges 46 and 47 whereby accidental axial displacement of the rollers from the tracks is positively prevented. A pair of bottom rollers 57 and 58 are mounted on shafts 61 and 62, respectively, which are supported on brackets 63 and `64, respectively, secured to the interior surface of the door at the opposite ends of the lower edge of the door. The rollers 57 and 58 are disposed respectively within the tracks 23 and 24 and are prevented from axial disengagement from within said tracks by the grooved flanges 43 and 44.

The counterbalance mechanism 13 is comprised of a pair of preferably coaxial shafts 67 and 68 which are rotatably supported near their remote ends in the outer bearings 71 and 72 (FIG. l) which are mounted upon the interior surface 21 of the wall 18 by the brackets 34 to the interior surface 21 of the wall 1S. A pair of conical pulleys 81 and 82 are secured to and rotatable with the remote ends of the shafts 67 and y68, respectively, and they have spiral grooves 83 and 84, respectively, in which cables 86 and 87, respectively, are received when the door is in its raised position of FIG. 4. The cable 86, for example, is secured at one end to the pulley 81 near its largest diameter and at its other end to the lower end of the corresponding edge of the door 11.

The shafts v67 and 68 are encircled by elongated spiral springs 88 and 89, respectively, which are secured near their remote ends to the shafts 67 and 68 by locking collars 92 and 93, respectively. The adjacent inner ends of said springs 88 and 89 (FIG. 5) are anchored on the bearing supports 76 and 77, respectively. The springs 88 and 89 are arranged so that they are tightened on the shafts 67 and 68 as the door is moved from its raised position (FIG. 4) to its lowered position (FIG. 2) thereby increasing the resistance of the springs to such downward movement as the effect of gravity on the lower edge of said door increases.

The shafts 67 and 68 are interconnected at their adjacent ends by a flanged coupling 94, and a sprocket 96 is secured to the shaft 68 for rotation therewith. The sprocket 96 is engaged by a chain 97, in this particular embodiment, which is connected to the operator 14 for the purpose of coordinating rotation of the shafts 67 and 68, hence the cables 86 and 87, with the movement of the operator 14, hence the door 11. Further details with respect to the door operator, its associated parts and its operation are set forth in said companion application.

The rail structure 16 comprises a pair of rails 98 and 99 which are mounted at their front ends upon the plate 78 and are supported intermediate their ends by a crossbar 102 extending between and secured to a pair of hangers 38 (FIG. 2). The operator 14 is mounted upon and movable along the rails 98 and 99 as it opens and closes the door 11.

OPERATION While the operation of the above-described door assembly will be apparent to persons skilled in the art from an examination of such description, the operation will now be summarized for convenience. Starting with the door 11 in its closed position of FIGS. l and 2, movement of the door toward the opened position of FIG. 4 is effected by the operator 14 as it moves rearwardly along the rails 98 and 99. The first movement of the door, due to the curved portions 28, 29 and 41, 42 of the supporting tracks, will be upwardly and rearwardly away from engagement with the wall 18. Thus, due to the slope in the said curved portions of the tracks, both the upper and lower ends of the door 1 are moved in substantially the same direction against the contrary urging of gravity. After the door has been moved approximately one foot upwardly and rearwardly away from the closed position, the rollers 48, 49 and 57, 58 will then be in substantially straight parts of the tracks 32, 33 and 23, 24, respectively. Accordingly, the door will then move into its opened position of FIG. 4 in a relatively conventional manner. That is, the upper end of the door is moved rearwardly by the operator 14 and the lower end of the door is moved upwardly. At the same time, the cables 86 and 87 are wound upon the pulleys 81 and 82, respectively, which are rotated in the winding direction by the action of the springs 88 and 89 on the shafts 67 and 68.

The operation during the initial stages of the closing of the door 11 may also be substantially conventional. However, just before the door reaches its closed position, the rollers supporting the door will move into the curved end portions of the tracks 23, 24 and 32, 33 whereby both the upper and the lower ends of the door will be moved substantially simultaneously in a downward and frontward direction. As a result, the seal 22 will be compressed between the door 11 and the wall 18, and the seal will be compressed between the lower edge of the door and the threshold 19; This compression of the seals 20 and 22 will continue automatically under the urging of gravity.

Because the door moves both downwardly and frontwardly in the last stage of its closing movement, an excellent seal is produced without excessive dragging movement between the seals 20 and 22 and the surfaces which come into contact with them. That is, there is a minimum of scrubbing movement between the seal 20 and the threshold 19 or between the seal 22 and the front side of the door 11.

Although movement of the door 11 away from its closed position of FIG. 2 will be opposed by a substantial force, the inclination of the curved portions 41, 42 is such (about 30 degrees) that the opening movement can be eifected manually by a normal adult, if the door is of average size. Thus, there will be no chance of having personnel trapped within the refrigerated room, even if the door operator malfunctions. In fact, since the front portions of the horizontal tracks 32 and 33 are curved upwardly and rearwardly, there will be no chance for the tracks to lock the door in its closed position. Accidental locking by the tracks can occur where the operator is not functioning since it must iirst move the upper end of the door horizontally. In a relatively large conventional door, it may be difficult to reach the upper end of the door for manual operation. However, due to the curved portions 41 and 42, the door 11 can be opened by grasping the lower end of the door and raising it.

MODIFIED STRUCTURE FIG. 6 illustrates a door 11A mounted within the opening 17A in a wall 18A. This arrangement can be accomplished by moving the upright tracks, one of which is shown at 24A, closer to the wall 18A and using a larger bracket 64A to mount the shaft 62A on the door 11A.

Because the door 11A is received within the opening 17A, the sealing element 22A extends around the entire peripheral adge of the door. In order to provide for a snug seal at the upper end (FIG. 7) of the modified door construction, the lower surface 106 of the lintel for the opening 17 is sloped upwardly toward the interior of the refrigerated room. The upper edge of the door 11A may be sloped infa corresponding manner.

The operation of the modified door 11A will be essentially identical with the operation of the door 11, except that the door 11A may have its interior surface ush with the interior surface of the wall 18A. It follows, of course, that the exterior side of the door 11A can be flush with the exterior surface of the wall 18A by appropriate adjustment in the location of the tracks and rollers with respect to the door and the wall.

FIG. 8 illustrates a cross-sectional view of a modified apparatus 110 for supporting a door 11B which moves substantially vertically between its opened and closed positions. The apparatus 110 includes lower tracks, one of which is shown at 24B, which tracks may be identical with the tracks 23 and 24 disclosed in FIG. 2 and described above. Thus, a roller 58B is mounted upon the lower end of the door 11B for guiding movement of the lower end of the door 11B along the track 24B.

A roller 49B is mounted upon the upper end of the door 11B about as the roller 49 is mounted upon the door 11. The roller 49B is disposed within a track 111 which also resembles the track 24. Specically, the track 111 has a lower portion 112 which curves frontwardly toward the header 113 of the door opening 17B while the remainder of the track 111 extends upwardly at a slightly diverging angle with the wall 18B.

The door 11B is raised by means including the cable 86B and the pulley 82B mounted on the shaft 67B. The shaft 67B can be positively driven by means not shown for raising and lowering the door.

As the door 11B is raised from its solid line, closed position FIG. 8, the initial movement of the entire door is rearwardly and upwardly along the curved lower portions of the tracks 24B and 111. After the rollers move out of such curved portions, the remaining movement of the door into the opened broken-line position of FIG. 8 is substantially vertical.

Although particular preferred embodiments of the invention have been described above for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.

The embodiments of the invention in which an exclusive property or privilege is claimed, are defined as follows:

1. lA structure adapted to support a one-piece, upwardly acting door for movement between an opened position and a closed, substantially upright position adjacent the edges of wall means defining an opening closed -by said door when in said closed position, comprising:

a pair of spaced, parallel and substantially upright tracks extending along the opposite side edges of said opening from points near the bottom thereof to points near the upper end thereof, the lower free end portions of said upright tracks being continuously arcuate in shape and curving toward said opening for causing said door to be guided increasingly laterally toward said opening to avoid wedging against said wall means;

a pair of spaced and parallel upper tracks extending from points near the opposite ends of the upper edge of said opening, the end portions of said upper tracks adjacent said wall means also being continuously arcuate in shape and curving toward said opening for causing said door to be moved laterally toward said opening to avoid wedging against said wall means;

upper and lower pairs of coaxial rollers mounted on said door near the upper and lower ends thereof, the upper rollers being engaged in said upper tracks for rolling movement therealong and the lower rollers being engaged in said upright tracks for rolling movement therealong, the iinal portion of the movement of both the upper and lower ends of said door into the closed position against said wall means having components both downwardly and toward said opening, the rollers being positioned within the arcuate end portions of the tracks when the door is in the closed position; and

resiliently flexible seal means engageable by and coacting between said wall means and said door along the full extent of the top, bottom and opposite side edges of said door when said door is in the closed position for sealingly closing said opening.

2. A door structure adapted to cooperate with an opening formed in wall means, comprising:

a one-piece, upwardly acting door for movement between an opened substantially horizontal position and a closed substantially upright position adjacent the edges of said wall means defining said opening, the opening being closed by said door when in said upright position;

a pair of spaced, parallel and substantially lhorizontal tracks extending from points near the opposite ends of the upper edge of said opening in one direction away from said wall means, the end portions of said horizontal tracks adjacent said wall means being continuously arcuate in shape and curving downwardly toward said opening for causing said door to be moved laterally toward said opening to avoid wedging against said wall means;

a pair of spaced, parallel and substantially upright tracks extending along the opposite side edges of said opening from points near the bottom thereof to points near the upper end thereof, the lower free end portions of said upright tracks being continuously arcuate in shape and curivng toward said opening for causing said door to be moved increasingly laterally toward said opening to avoid wedging against said Wall means;

upper and lower pairs of coaxial rollers mounted on said door near the upper and lower ends thereof, the upper rollers being engaged in said horizontal tracks for rolling movement therealong and the lower rollers being engaged in said upright tracks for rolling movement therealong, the rollers being positioned within the arcuate end portions of the tracks when the door is in the upright closed position;

resiliently flexible seal means engageable by and between said wall means and said door along the full extent of said edges dening said opening when said door is in the closed upright position; and

counterbalance means operatively connected to the door for counteracting the force of gravity and facilitating the opening and closing of the door, said counterbalance means including spring biased pulley means mounted on said wall means above said opening and cable means connected at one end to said door near the lower end thereof, the other end of said cable means being connected to said pulley means so that movement of said door from said horizontal position into said upright position `is yieldably op- 4. A door structure according to claim 2, wherein said resiliently flexible seal means includes an elongated resilient seal member tixedly secured to and extending longitudinally along the complete length of the lower edge of said door.

5. A door structure according to claim 4, further including operator means interconnected to said door for permitting same to be automatically moved between said opened and closed positions.

6. A door structure according to claim 5, wherein a shaft is rotatably supported on said'wall means directly above said opening, said counterbalance means including a pulley nonrotatably mounted on said shaft and a torsion spring having one end thereof xedly secured relative to said wall means and the other end thereof nonrotatably secured relative to said shaft, and said operator means including a pulley means nonrotatably secured to said shaft and an elongated flexible drive member disposed in driving engagement with said pulley means.

References Cited UNITED STATES PATENTS '1,252,448 l/19l8 Kees 49-197 1,316,677 9/1919 Boughton 49-200 1,855,953 4/1932 Friedrich 49--197X 2,071,161 2/1937 Cornell et al 49--200 3,160,200 12/1964 McKee et al. 49-200X pENNls L. ,'rAYLoR, Primary Examiner 

